Abstract: A method for damping oscillations in a tower of a wind turbine includes determining a primary rotational frequency of the rotor (fp) that correlates to a tower resonance frequency (fr). The method defines an exclusion zone between a first rotational frequency of the rotor (f1) that is less than the primary rotational frequency (fp) and a second rotational frequency of the rotor (f2) that is greater than the primary rotational frequency (fp). At rotor frequencies below the exclusion zone, a first tower-damping force strategy is applied. At rotor frequencies above the exclusion zone, a second tower-damping force strategy is applied that is different from the first tower-damping force strategy.

Abstract: A system and method are provided for controlling a wind farm during low wind speeds. Accordingly, the farm controller designates at least one of the plurality of wind turbines of the wind farm as a designated turbine. The designated turbine is operating in a full auxiliary mode when the speed of the wind acting on the wind farm is below a wind speed threshold. The remaining wind turbines are operated in a reduced auxiliary mode. The reduced auxiliary mode includes the disabling of at least one of pitching and yawing of the remaining wind turbines. When a power output for the designated wind turbine exceeds a power threshold, the farm controller directs at least one group of the remaining wind turbines to transition from the reduced auxiliary mode to the full auxiliary mode. During certain grid conditions, the transition between auxiliary modes may be delayed.

Abstract: A method for protecting a wind turbine from overloading during operation caused by a fault includes receiving, via a controller, a plurality of pitch signals from a plurality of pitch control mechanisms of a pitch system of the wind turbine, the pitch system configured to rotate a plurality of rotor blades mounted to a rotatable hub of a rotor of the wind turbine about respective pitch axes. Further, the method includes determining a collective pitch rate of the pitch system as a function of the plurality of pitch signals. The method also includes defining a minimum pitch rate threshold that varies with a speed parameter of the wind turbine. Moreover, the method includes receiving a first speed parameter of the wind turbine. In addition, the method includes comparing the collective pitch rate to the minimum pitch rate threshold for the first speed parameter. Thus, the method includes controlling the wind turbine based on the comparison.

Abstract: A method for protecting a wind turbine from overloading during operation caused by a fault includes receiving, via a controller, a plurality of pitch signals from a plurality of pitch control mechanisms of a pitch system of the wind turbine, the pitch system configured to rotate a plurality of rotor blades mounted to a rotatable hub of a rotor of the wind turbine about respective pitch axes. Further, the method includes determining a collective pitch rate of the pitch system as a function of the plurality of pitch signals. The method also includes defining a minimum pitch rate threshold that varies with a speed parameter of the wind turbine. Moreover, the method includes receiving a first speed parameter of the wind turbine. In addition, the method includes comparing the collective pitch rate to the minimum pitch rate threshold for the first speed parameter. Thus, the method includes controlling the wind turbine based on the comparison.

Abstract: A method for reducing extreme loads acting on at least one rotor blade of a wind turbine includes calculating, via a processor, a flapwise bending moment of the rotor blade(s). Further, the method includes calculating, via the processor, an edgewise bending moment of the rotor blade(s). The method also includes calculating, via the processor, an average load envelope of a blade root bending moment of the rotor blade(s) as a function of the flapwise bending moment and the edgewise bending moment of the rotor blade(s). Moreover, the method includes calculating, via the processor, an overall load envelope of the blade root bending moment of the rotor blade(s) as a function of the average load envelope and a future load estimation of the blade root bending moment of the rotor blade(s). As such, the method also includes implementing, via the processor, a control action when the overall load envelope is above a certain threshold.

Abstract: A wind turbine control system is disclosed. The wind turbine control system includes a wind turbine, at least one sensor configured to detect at least one environmental condition associated with the wind turbine, and a wind turbine controller communicatively coupled to the wind turbine and the at least one sensor. The wind turbine controller includes at least one processor in communication with at least one memory device. The at least one processor is configured to retrieve at least one wind condition variable associated with the wind turbine, retrieve a power curve, the power curve generated based on the at least one wind condition variable by computing, for each of a plurality of wind speed values, a power value, receive, from the at least one sensor, sensor data, and control the wind turbine using the generated power curve based on the received sensor data.

Abstract: A method for operating a wind turbine includes operating, via a controller, the wind turbine according to a speed set point during normal operation of the wind turbine. The method also includes receiving, via the controller, a command to shut down the wind turbine or to curtail operation of the wind turbine. In response to receiving the command, the method includes initiating, via the controller, a shutdown procedure or a curtailment procedure of the wind turbine. During the shutdown procedure or the curtailment procedure of the wind turbine, the method includes dynamically adjusting a rate of change of the speed set point as a function of a speed tracking error, which corresponds to a difference between an actual rotor speed of the wind turbine and the speed set point.

Abstract: A method for operating a wind turbine includes operating, via a controller, the wind turbine according to a speed set point during normal operation of the wind turbine. The method also includes receiving, via the controller, a command to shut down the wind turbine or to curtail operation of the wind turbine. In response to receiving the command, the method includes initiating, via the controller, a shutdown procedure or a curtailment procedure of the wind turbine. During the shutdown procedure or the curtailment procedure of the wind turbine, the method includes dynamically adjusting a rate of change of the speed set point as a function of a speed tracking error, which corresponds to a difference between an actual rotor speed of the wind turbine and the speed set point.

Abstract: Methods and systems for detecting rotor blade damage in a wind turbine are provided herein. A monitoring system includes a filter module and a damage determination module. The filter module is configured to determine an amplitude of a 1P frequency component of at least one operating condition of the wind turbine. The damage determination module is configured to compare the determined 1P frequency component amplitude to a threshold 1P frequency component amplitude.

Abstract: A method for sensing a position of a lead wire during winding of a wire on a coil form to form a precision coil is provided. The method includes acquiring data representative of at least a portion of the precision coil, identifying portions of the acquired data that represent the wire in the precision coil, and determining a position of the lead wire on the coil form from the identified portions of the acquired data.

Abstract: Methods are provided for controlling wind turbine loading. In one embodiment, a method includes the steps of determining a current thrust value for the wind turbine, calculating a thrust differential based on the current thrust value and a predetermined maximum thrust value, calculating a desired pitch offset value based on the thrust differential and a thrust sensitivity value, and adjusting a pitch of the wind turbine utilizing the pitch offset value.

Abstract: A method for sensing a position of a lead wire during winding of a wire on a coil form to form a precision coil is provided. The method includes acquiring data representative of at least a portion of the precision coil, identifying portions of the acquired data that represent the wire in the precision coil, and determining a position of the lead wire on the coil form from the identified portions of the acquired data.

Abstract: Methods and systems for detecting rotor blade damage in a wind turbine are provided herein. A monitoring system includes a filter module and a damage determination module. The filter module is configured to determine an amplitude of a 1P frequency component of at least one operating condition of the wind turbine. The damage determination module is configured to compare the determined 1P frequency component amplitude to a threshold 1P frequency component amplitude.

Abstract: Methods are provided for controlling wind turbine loading. In one embodiment, a method includes the steps of determining a current thrust value for the wind turbine, calculating a thrust differential based on the current thrust value and a predetermined maximum thrust value, calculating a desired pitch offset value based on the thrust differential and a thrust sensitivity value, and adjusting a pitch of the wind turbine utilizing the pitch offset value.

Abstract: Wind turbines and methods for controlling wind turbine loading are provided. In one embodiment, a method includes the steps of determining a current wind speed. The method further includes determining a tip speed ratio and a pitch angle that maximize a power coefficient under at least one of the following conditions: a thrust value is less than or equal to a pre-established maximum thrust, a generator speed value is less than or equal to a pre-established maximum generator speed, or a generator torque is less than or equal to a pre-established maximum generator torque. The method further includes calculating a desired generator speed value based on the current wind speed and a tip speed ratio. The method further includes calculating a desired generator power value based on the desired generator speed value.

Abstract: A magnetic bearing system includes a first electromagnet, a second electromagnet opposing the first electromagnet, and a rotor positioned between the first and second electromagnets. The first and second electromagnets are configured to apply a magnetic force. The system also includes a controller configured to determine a control action necessary to move the rotor to a predetermined rotor setpoint. The system further includes a nonlinear compensation device configured to calculate a first electrical current setpoint for the first electromagnet and a second electrical current setpoint for the second electromagnet to maintain a predetermined stiffness during at least one of startup, operation, and shutdown of the magnetic bearing system. The first and second electrical current setpoints are calculated based on the control action determined by the controller.

Abstract: A wind turbine control system includes a detecting unit for adjusting a reference nodding moment of a wind turbine rotor based on at least one of an aerodynamic thrust on the wind turbine rotor and a speed of wind; a compensating unit for determining a physical nodding moment of the wind turbine rotor, comparing the physical nodding moment with the reference nodding moment, and using the comparison to compute a pitch angle command for at least one wind turbine blade; and a driving unit for changing a pitch of the at least one blade based on the pitch angle command to control the physical nodding moment of the wind turbine rotor.

Abstract: A method for operating a wind turbine is based on providing a wind turbine that includes a control system programmed to adjust a blade pitch angle of one or more rotor blades without knowledge of rotor blade efficiency. A blade pitch angle of one or more rotor blades is adjusted in response to the current conditions experienced by the wind turbine to provide a blade pitch angle that is greater than or equal to a blade pitch angle necessary to maintain a predetermined minimum rotor stall margin according to modeled aerodynamic performance of the rotor blades such that continuous operation of the wind turbine is maintained without transitions to the stalled mode.

Abstract: An apparatus and method for reducing asymmetric rotor load in a wind turbine includes calculating a time delay for pitching each blade toward feather upon initiation of a shutdown condition. The blades with the larger blade angle begin moving toward feather with an initial pitch rate, while the blade with the smallest blade angle begins moving toward feather with a final pitch rate. Once all the blades have reached approximately an identical blade angle, the blades move simultaneously together to feather at the final pitch rate. By introducing the time delay for pitching the blades having higher blade angles at the final pitch rate, a simple, time-based correction of initial conditions during shutdown reduces the extreme loads on turbine components.

Abstract: A method, system and computer program product for operating a wind turbine is disclosed. For operating the wind turbine a set of operational data points are sensed via a sensing module. The set of operational data points may include bending stress values. Based on the bending stress values, a load scenario indicator value may be computed. Further, based on the set of operational data points a loading threshold value may be obtained. At least one operating parameter of the wind turbine is changed if the load scenario indicator value exceeds the loading threshold.